放線菌5012之角蛋白酶及不同前處理(20%酒精及0.05M NaOH)對雞腳皮膜分解效果之研究

Abstract

Scutate scale is a layer on epidermis of avian that protected and isolated from outer environment. Scutate scales came from apoptosis of epidermis cells and became a scaly structure with mounts of lipid. With the development of poultry industry, wastes composed of keratin are rapidly accumulated and resulted in a serious pollution problem on environment. In the past, using keratin wastes as feedstuff had been reported and generally focused on poultry feather and pig hair. No report or information about chicken scutate scales was evidenced to apply in animal feedstuff. However, chicken scutate scales were not only composed of high protein also contained aboundant amount of lipid. Therefore, the objective of this study was divided into two parts, the first part was to evaluate the protease and keratinase activity of Actinomycetes 5012 was incubated with chicken scutate scales. The second part was use of 20% alcohol, 0.05M sodium hydroxide for 24 and 36 hours as pretreatment then treated by different ratio of enzyme and substrate (raw keratinase from Actinomycetes 5012 / chicken scutate scales) and tried to obtain the optimum condition depended on soluble protein in solution and digestive protein in chicken scutate scales. In the chemical compositions, chicken scutate scales with 20% alcohol pretreatment had the highest protein content and both of chicken scutate scales with sodium hydroxide pretreatments also had higher ash value than the others. However, all samples showed high mount of ether extract (about 20%) and this result indicated the lipid in chicken scutate scales was belonged to wax which was high molecular weight in fat. The results of the first part were showed that Actinomycetes 5012 and 2% scutate scale in substrate had the highest keratinase activity (29.0 U) at day 7 during incubation. The highest soluble protein of the ratio of enzyme and substrate was found in 100:1 and the value was . The digestive protein of dry chicken scutate scales and 20% alcohol pretreatment increased when treated with enzymes during incubation. Dry chicken scutate scales treated with enzyme for 14 days had the highest digestive protein (53.72%) in all treatments. Nevertheless, chicken scutate scales treated with sodium hydroxide had higher soluble protein in solution but lower digestive protein existed in substrate after enzyme treatment. In the scanning electron microscope observation, some protein fractions were found on the suface of chicken scutate scales with alkine and enzyme treatment for 14 days. Also, some significantly destroied traces were exhibited on the surface of chicken scutate scales in all treatment after incubating with raw enzymes from Actinomycetes 5012 in this research. In conclusion, use of raw enzymes from Actinomycetes 5012 and alkine pretrement was an effiecient performing method to increase the digestive protein and soluble protein of chicken scutate scales and also to elevate added value of chicken scutate scales in animal feed in the future.